Published: 29 January 2020
smtp_mailaddr in smtp_session.c in OpenSMTPD 6.6, as used in OpenBSD 6.6 and other products, allows remote attackers to execute arbitrary commands as root via a crafted SMTP session, as demonstrated by shell metacharacters in a MAIL FROM field. This affects the "uncommented" default configuration. The issue exists because of an incorrect return value upon failure of input validation.
From the Ubuntu security team
It was discovered that OpenSMTPD incorrectly verified the sender's or receiver's e-mail addresses under certain conditions. An attacker could use this vulnerability to execute arbitrary commands as root.
CVSS 3 base score: 9.8
Launchpad, Ubuntu, Debian
|Ubuntu 21.10 (Impish Indri)||
|Ubuntu 21.04 (Hirsute Hippo)||
|Ubuntu 20.04 LTS (Focal Fossa)||
|Ubuntu 18.04 LTS (Bionic Beaver)||
|Ubuntu 16.04 ESM (Xenial Xerus)||
(end of standard support, was needed)
|Ubuntu 14.04 ESM (Trusty Tahr)||
Does not exist
- https://github.com/OpenSMTPD/OpenSMTPD/commit/be6ef06cba9484d008d9f057e6b25d863cf278ff (opensmtpd-6.4.0)